The ostrich is a swift-running flightless bird. It can reach speeds of up to sixty kilometres per hour, is a herbivore and a herd animal and is constantly in the company of other grazing animals, such as antelopes and zebras. The males have black and white feathers, while the females are grey-brown in colour. Ostriches are the last of the two-toed birds and are the largest living birds by far. Their eggs could contain more than twenty-four chicken eggs each. By the end of the 18th century they were threatened by extinction due to being hunted for the sake of their tail and wing feathers. The ostrich is well adapted to the grasslands and savannah of central and southern Africa where it thrives in the natural state. The custom of breeding ostriches grew from the middle of the 19th century. Today the ostrich is no longer desired purely for its feathers. Its skin is processed into exquisite leather goods. Its meat is a tasty and healthy delicacy enjoyed throughout the world.